蛋白酶体抑制剂Lactacystin对胶质瘤C6细胞的增殖抑制作用及其机制

目的：通过观察蛋白酶体抑制剂Lactacystin（LAC）对C6细胞增殖率的影响，探讨LAC引起胶质瘤细胞增殖率发生改变的机制，为临床上治疗胶质瘤提供理论依据。方法：体外培养大鼠胶质瘤C6细胞，选择处于对数生长期的细胞，实验分为对照组、LAC 2.5 μmol/L组、LAC 5.0 μmol/L组及LAC 10.0 μmol/L组，MTT法检测各组C6细胞增殖率，流式细胞术检测细胞凋亡和线粒体膜电势，RT-PCR方法检测各组细胞中Bax和bcl-2 mRNA表达，Western blotting方法检测各组细胞中Bax、bcl-2和P65 蛋白表达。结果：与对照组比较，LAC 5.0 μmol/L组和LAC 10.0 μmol/L组细胞增殖率、线粒体膜电势和P65蛋白表达水平降低（P<0.05），而细胞凋亡率、Bax/bcl-2 mRNA和蛋白的比值增加（P<0.05）。结论：LAC通过诱导细胞凋亡抑制C6细胞的增殖率，其引起凋亡的方式可能是通过线粒体途径，此外在这个过程中NF-κB信号通路也可能影响细胞的增殖率。

Inhibitory effect of proteasome inhibitor Lactacystin on proliferation of glioma C6 cells and its mechanism

Objective To study the mechanism of the changes of proliferation rate induced by the proteasome inhibitor Lactacystin (LAC) through observing the effect of LAC on the proliferation rate of glioma C6 cells,and provide a theoretical basis for clinical treatment of glioma.Methods The cultured rat glioma C6 cells at the logarithmic growth phase were divided into control group,LAC 2.5μmol·L~(-1) group,LAC 5.0 μmol·L~(-1) group and LAC 10.0μmol·L~(-1) Group.MTT assay was used to detect the proliferation rate of C6 cells.FCM was used to detect the death and mitochondrial membrane potential of C6 cells and RT-PCR was performed to examine the Bax and bcl-2 mRNA expressions,Western blotting was used to determine the Bax,bcl-2 and P65 protein expressions.Results Compared with control group,the proliferation rates of C6 cells,mitochondrial membrane potential and the level of P65 protein expression in LAC 5.0 and LAC 10.0 μmol·L~(-1) groups were reduced (P<0.05),while the apoptotic rate,Bax/bcl-2 mRNA and protein ratio were increased (P<0.05).Conclusion LAC can inhibit the proliferation rate of C6 cells by inclucing the apoptosis of C6 cells,which may be related to the mitochondrial pathway,in addition,NF-κB signaling pathway may also affect the proliferation rate of the C6 cells in this process.